Method of impregnating concrete bodies and porous ceramic products with bituminous material



' and brackish water, alkaline soil solutions, orperature of the asphalt being maintained, suf- 6Q;

1,10v Various methods have been proposed iortreat- 1y attended with ircthing and this step in the 29 effectiveand shortens the process as a whole. this dry condition, is placed in aclosed tank from 7,5

.25, is miscible, such oil preferably consisting of a in the oil. After .a few minutes or" such immersion '35 be the-casewithout the preliminary-oil treat- Whether the tank be the same or a different 40 the open tank treatment and the vacuum'tank sure is then introducedandgradually increased 45 ously dried, is immersed in oil in an open tank and deemed necessary. I

Patented Nov. 28, 1933 I I r I v UNITED" STATES PATENT OFFICE METHOD 0F IMPREGNATING CONCRETE BODIES AND POROUS CERAMIC PROD- Uc s WITH BITUMINOUS ATERIAL Edwin C. Wallace, Newton, Mass assignor to WarrenBrothers Company, Cambridge, Mass, a'corporation of West Virginia No Drawing. Application August 20, 1930 Serial No. 476,726

8 Claims. (01. 91-70) This invention relates to processes and methfitration by the bituminous material when the ods of treating concrete bodies such as piles, pile latter is applied. 1 caps,-sewer pipes, conduits, fence posts, etc., to Alter draining, the article or body is immersed render them more resistantto the action of salt in heated asphalt, also in an open tank, the temganic matter, sewer gases, etc. a ficiently high-to permit its penetration into the It is obvious that the processwould also apply pores of thebody, This temperature willordito clay or ceramic products of similar nature and narilyrange between 259 and 450 F. The heatsubjected to the same destructive action. c ing of the asphalt to this temperature is generaling such bodies, the most practicalof which aptreatment is prolonged until frothing ceases.

pears to be the application of a protective coat- The temperature is then reduced and the artiing of bituminous material or asphalt to the cle removed before the asphalt congeals, when body to be protected. the body will be found to have an eiiective bitumil5 j To secure efiective penetration of the bituminous sheathing fully adherent by reason of the 70 nous material into the pores of the body is the penetration of the bitumen into the pores due to chief problem and the object of the present in-' thepreviously applied oil leader. vention is to provide a preliminary treating step In the vacuum tank treatment the article is which accelerates the penetration, makes it more preferably dried before treatment and, while in The preliminary treatment consists in the apwhichthe air is withdrawn, by a vacuum pump. plication to the body or article to be impreg- After a short interval, say-ten to twenty minutes, nated, of a penetrating, mobile, readily diffusive the oil is introduced into the. tank without adoil, with which bituminous material. or asphalt mitting air, so that the body becomes immersed mixture of cyclic and open chain hydrocarbons air'is slowly admitted until atmospheric pressure of specific gravity ranging from .8 to 1.1 and obtains, This pressure issunicient-to eirectively volatility not exceeding one-third of its volume inject the oil into the poresof thehody. in five hours at 100 C. with viscosity generally After this preliminary oil treatment in the.

30 under 200 seconds at-25 C. in the Engler viscosimclosed tank, the article is subjectedto treatment 85 eter. This oil is absorbed into the pores of the with the bituminous material or asphalt in the body or article where it serves as a leader for the same or a similar tank and such treatment may bituminous coating later applied, causing it to follow immediately after the oil treatment, or permeate the body to a greater depth than would after an interval of several days.

ment. L I tank, it is emptied, except for the bodies or arti- Various ways of applying the oil treatment and cles to .be treated, and then exhausted of air.

the subsequent asphalt coating may be employed, Heated asphalt is then introduced and thebodies but the most practical, so far as now appeals-are submerged inthe same for a short time. Prestreatment (as they are referred to herein), and to the desiredmaximum, which is sometimes as variations of the two. high as 150 lbs. or more per square inch.

- In the open tank treatment the article to be Withincreasing pressure the temperature of impregnated, which may or may not-be previthe asphalt may be raised as high as may b heated to a temperature slightly above the boil- According to the size of the bodies or articles ing point of water, for example, 220 to 250 F. this impregnation period varies from a fewhours The body orv article is permitted to remain in for small articles easily impregnated, to a day the oil bath until it has acquired the temperature or longer for large articles diiiicult to impreg ,50 of the oil, when the whole is permitted to cool and nate, such as piles, pile caps, etc. The depth of 5 5 ing the effectiveness of the oil in inducing peneto several inches with more porous material. In

the article or body removed and drained of the the impregnation varies according to the densesurplus oil. ness of the material with which the article or This draining period may be anywhere from body is formed, and may range anywhere from half an hour to a week or longer without impaira fraction of an inch with very. dense material,

every case, however, it must be" suflicient to form an effective protective coating on all exposed surfaces of the article, and in hollow articles such as sewer pipe, pile caps, conduits and the like, to form a protective coating on both the inner and outer surfaces.

The preliminary oil treatment increases the adhesion of the bituminous material or asphalt to the treated article, so that it does not readily chip or? in handling, and injaddition it effects better penetration into the pores and shortens the time required to impregnate.

The method is susceptible of variations of the two plans outlined above, as by applying the oil under the open tank method and the bituminous coating under the vacuum tank method, or vice versa.

When the oil treatment is applied in the vacuum tank, the article to be treated is dried before being placed in the tank and heating of the oil is unnecessary. in fact, the boiling point of the oil is so reduced in a vacuum that excess heat is to be avoided to prevent volatilization.

It has been found in practice that concrete articles will take up from 2% to 5% of oil by weight in the preliminary oil treatment.

In the open tank treatment, the body or article may or may not be dried before introduction into the oil, but in vacuum tank treatment, the article is preferably dried, either by heating in an oven or kiln at a temperature slightly above the boiling point of water, as for example, 220 to 240 F., or by placing in a current of dry air which may be slightly warm.

The invention having been described, what is claimed as new and useful is:

1. The method for impregnating concrete bodies and porous ceramic products which comprises the initial drying of the article to be treated, then its immersion, in the presence of heat, in a bath of a penetrating, mobile, volatile hydrocarbon oil with which asphalt is miscible, then draining the article of surplus oil, and final- 1y submerging it in asphalt heated to a temperature which will vaporize sufficient oil to facilitate the impregnation of the concrete by the asphalt.

2. The method for impregnating concrete bodies and porous ceramic products which comprises the immersion of the article to' be treated in a penetrating, mobile, volatile hydrocarbon oil with which asphalt is miscible, the oil being heated to a temperature slightly above the boiling point of water and the immersion being continued until the article has acquired the temperature of the oil, then removing and draining the article of surplus oil after having allowed it to cool in the oil bath,-and finally submerging the article in asphalt heated to a temperature which will vaporize suificient oil to facilitate the impregnation of the concrete by thev asphalt.

3. The method for impregnating concrete bodies and porous ceramic products which cornprises the initial drying of the'article to be treat- 'ed, then its immersion in a penetrating, mobile,

acquired the temperature" of the oil, then removing and draining the article of surplus oil after having allowed it to cool in the oil bath, then submerging the article in asphalt heated in an open tank to a temperature within range of 300 F. to 450 F. and prolonging this treatment until any indication of frothing disappears, and then reducing the temperature and removing the article before the asphalt congeals.

- 4. The method for impregnating concrete bodies and porous ceramic products which comprises first subjecting the article to be treated to a volatile oil bath in a vacuum, then after a short interval admitting air until atmospheric pressure obtains, and finally applying asphalt under pressure heated to a temperature which will vaporize sufficient oil to facilitate the impregnation of the concrete by the asphalt.

5. The method for impregnating concrete bodies and porous ceramic products which comprises first subjecting the article to be treated me volatile oil bath in a vacuum, then after a short interval admitting air until atmospheric pressure obtains, and finally applying asphalt under pressure heated to a temperature which will vaporize sufficient oil to facilitate the impregnation of the concrete by the asphalt, the pressure being gradually increased and the temperature of the asphalt correspondingly raised.

6. The method of providing concrete bodies and porous, ceramic products with a protective coating which comprises immersing the article in volatile oil in the presence of heat until the oil permeates the pores of the body, then draining off excess oil and immersing the body in asphalt or bituminous material heated to a temperature which will vaporize sufficient oil to facilitate the impregnation of the concrete by the asphalt, and then after allowing the mass to cool removing the treated article prior to congelation of the bituminous material.

7. The method of impregnating concrete bodies and porous ceramic products which comprises placing the articles to be treated, in dried condition, in a closed tank; then exhausting air; then introducing a mobile penetrating hydrocarbon volatile oil to submerge the articles; then later admitting air to a normal pressure and after a short interval withdrawing the oil and again exhausting the air and then introducing asphalt or bitumen of similar nature heated to a temperature which will vaporize sufficient oil to facilitate the impregnation of the concrete by the asphalt; thenincreasing pressure and temperature and maintainingsame for a time; then after allowing the mass to cool removing the treated articles before the bitumen congeals.

8. The method of impregnating concrete bodies and porous ceramic products which comprises the initial drying of the article tobe'treated, then its immersion, in a bath of a penetrating, mobile, volatile hydrocarbon oil with which asphalt is miscible, then draining the article of surplus oil, and finally submerging it in asphalt heated to a temperature sufiicient to vaporize part of the oil to facilitate the impregnation of the body by the viscous bituminous material.

EDWIN C. WALLACE. 

